In general, a work line module is a combination of a plurality of work machines for machining workpieces, each work machine having a specified machining purpose and non-work facilities for operating operation other than machining the workpieces, for example, washing, drying and assembling (Patent document No. 1). In order to increase a manufacturing capacity of the work line module, a number of the machines including work machines and non-work facilities have to be increased. Thus, an investment for increasing manufacturing capacity has to be remarkably increased. It is necessary to increase a number of the all machines and facilities. However, if an actual production amount is less than an estimated amount, it is considered that machines and facilities newly invested are redundant and an investment newly added is excessive.
Recently, in the all industry field, it is required to provide a manufacturing line of which a manufacturing capacity is always suitable for an amount currently demanded and a number of machines/facilities can be varied depending on industrial demand. However, in a machine manufacturing line, it is difficult to provide such a variable manufacturing line, since a purpose of each machine is simply specified such as machining, furnishing, assembling, cleaning, leak detecting, measuring and drilling. It had not been developed a composite machine/facility for improving manufacturing efficiency and a compact conveying device for arranging a plurality of composite machines/facilities in a line.